1. Field of the Invention
One embodiment of the present invention relates to an imaging device, a monitoring device, and an electronic appliance which have a function of taking an image.
Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method. In addition, one embodiment of the present invention relates to a process, a machine, manufacture, or a composition of matter. Specifically, examples of the technical field of one embodiment of the present invention disclosed in this specification include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, a method for driving any of them, and a method for manufacturing any of them.
2. Description of the Related Art
Imaging devices are normally incorporated in mobile phones, and have come into widespread use (e.g., Patent Document 1). In particular, CMOS imaging sensors have advantages of low price, high resolution, low power consumption, and the like as compared with CCD image sensors. A CMOS image sensor accounts for the most part of an imaging device.